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perf(dvb): Lazy OCR initialization for DVB subtitle decoder #1943

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Merged
cfsmp3 merged 1 commit into from
Jan 1, 2026
Merged

perf(dvb): Lazy OCR initialization for DVB subtitle decoder #1943

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13 changes: 12 additions & 1 deletion src/lib_ccx/dvb_subtitle_decoder.c
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Original file line number Diff line number Diff line change
Expand Up @@ -182,6 +182,7 @@ typedef struct DVBSubContext
LLONG time_out;
#ifdef ENABLE_OCR
void *ocr_ctx;
int ocr_initialized; // Flag to track if OCR has been lazily initialized
#endif
DVBSubRegion *region_list;
DVBSubCLUT *clut_list;
Expand Down Expand Up @@ -442,7 +443,11 @@ void *dvbsub_init_decoder(struct dvb_config *cfg)
}

#ifdef ENABLE_OCR
ctx->ocr_ctx = init_ocr(ctx->lang_index);
// Lazy OCR initialization: don't init here, wait until a bitmap actually needs OCR
// This avoids ~10 second Tesseract startup overhead for files that have DVB streams
// but don't actually produce any bitmap subtitles (e.g., files with CEA-608 captions)
ctx->ocr_ctx = NULL;
ctx->ocr_initialized = 0;
#endif
ctx->version = -1;

Expand Down Expand Up @@ -1701,6 +1706,12 @@ static int write_dvb_sub(struct lib_cc_decode *dec_ctx, struct cc_subtitle *sub)
// Perform OCR
#ifdef ENABLE_OCR
char *ocr_str = NULL;
// Lazy OCR initialization: only init when we actually have a bitmap to process
if (!ctx->ocr_initialized)
{
ctx->ocr_ctx = init_ocr(ctx->lang_index);
ctx->ocr_initialized = 1; // Mark as initialized even if init_ocr returns NULL
}
if (ctx->ocr_ctx)
{
int ret = ocr_rect(ctx->ocr_ctx, rect, &ocr_str, region->bgcolor, dec_ctx->ocr_quantmode);
Expand Down
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